The fields of use of such spectrometers are manifold. Typical applications are, for example, in colour detectors for the graphic industry or the food industry, in apparatus for the control of industrial processes, in measuring apparatus for clinical diagnostics, and so on.
A known generic spectrometer is described, for example, in EP-A-0 489 286. In this known measuring head, the carrier body is constructed as a relatively thick bi-convex lense, whereby the light entry gap and the photoelectric converter arrangement, which is constructed as a diode line, are positioned on one and the diffraction grating is positioned at the other of the curved surfaces of the bi-convex lense. With this construction, a relative simple manufacture and adjustability with good optical correction is achieved, however this construction requires the use of a curved, in general aberration-corrected, concave grating.
This requirement can be avoided with the use of spectrometers according to the Fastie-Ebert-principle--as described, for example, in the patent specification U.S. Pat. No. 4,744,618 "Demultiplexer". However, such spectrometers have the disadvantage that they can only be operated in general in positive defraction order and with an inclined grating--as shown, for example, in FIG. 11 of the mentioned patent specification, U.S. Pat. No. 4,744,618.